Passenger vehicles for roadways, such as cars, trucks, or other automobiles, typically include doors with windows that are retractable into cavities of the doors. However, traditional internal door structures, such as those for transferring loading to a vehicle body of the vehicle during standardized loading events (e.g., standard dynamic and quasi-static loading during test procedures under Federal Motor Vehicle Safety Standards (FMVSS) 214), require that the windows be retracted into positions that are spaced apart from an end of the door. For example, a traditional load transferring door structure extends inboard across an inboard-outboard thickness of the door, so as to be in close proximity to the vehicle body (e.g., an A-, B-, or C-pillar) for transferring the standard loading thereto. As a result, this load transferring structure occupies the volume of the door cavity at its forward and/or rearward ends, which prevents the window from being retracted into the end volumes. With the window being spaced apart from the forward and/or rearward ends of the door when retracted, the edge of the window must similarly be spaced apart a noticeable distance (e.g., several inches) from the end of the door when the window is raised. For example, a forward edge of the window may be spaced rearward of a forward end of a front door, or a rearward edge of the window may be spaced forward of a rearward end of a rear door. Accordingly, traditional doors for passenger vehicles include fixed or non-retractable structures to fill a gap formed between the visible door structure (e.g., above the beltline or outer door panel), forward or rearward window edge, and vehicle body (e.g., A- or C-pillar). Such fixed structures may include various combinations of fixed window panels, opaque panels, mirror attachments, window frames, etc., which may interrupt or block a passenger's view outside the vehicle and may limit an openable region of the door. Placement of these fixed structures also results in a discontinuous or interrupted cut line (i.e., visible division between vehicle components) between the vehicle body (e.g., including the A- or C-pillar, front or rear quarter panel), and the window and visible door panel.